An eighth order channel selection filter for low-IF and zero-IF DVB tuner applications

作     者：邹亮 廖友春 唐长文 

作者机构：ASIC & System State Key LaboratoryFudan University Ratio Microelectronics Technology CoLtd 

出 版 物：《Journal of Semiconductors》 (半导体学报（英文版）)

年 卷 期：2009年第30卷第11期

页      面：79-87页

核心收录：

学科分类：0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 080902[工学-电路与系统] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0702[理学-物理学] 

基　　金：Project supported by the National High Technology Research and Development Program of China (No.2007AA01Z282) 

主　　题：active-RC filter Butterworth frequency tuning group delay noise linearity 

摘      要：An eighth order active-RC filter for low-IF and zero-IF DVB tuner applications is presented, which is implemented in Butterworth biquad structure. An automatic frequency tuning circuit is introduced to compensate the cut-off frequency variation using a 6-bit switched-capacitor array. Switched-resistor arrays are adopted to cover different cut-off frequencies in low-IF and zero-IF modes. Measurement results show that precise cut-off frequencies at 2.5, 3, 3.5 and 4 MHz in zero-IF mode, 5, 6, 7 and 8 MHz in low-IF mode can be achieved, 60 dB frequency attenuation can be obtained at 20 MHz, and the in-band group delay agrees well with the simulation. Two-tone testing shows the in-band IM3 achieves -52 dB and the out-band IM3 achieves -55 dB with -11 dBm input power. This proposed filter circuit, fabricated in a SMIC 0.18μm CMOS process, consumes 4 mA current with 1.8 V power supply.